The planned studies will be a continuation of ongoing projects that reflect a long interest in abnormal growth regulation in the human hematopoietic system. 1. Combined chromosomal and molecular studies, with Dr. Carlo Croce and others, of specific genes involved in human lymphoid and myeloid neoplasms and mechanisms leading to altered gene function. 2. Longitudinal cytogenetic studies in chronic B cell and T cell disorders correlated with clinical, biological, and immunological characteristics of these neoplasms. 3. Further investigation of altered growth regulation in chronic B cell and T cell disorders, including inhibitory factors (transforming growth factor-beta), stimulatory factors, and the role of autoreactivity in B-CLL. (This grant is a component of the University of Pennsylvania Cancer Center)